Neutral Base Version (HSF51xx): Prepare surface by sanding with 220-grit sandpaper. Remove all dust, oil and solvent from the surface. Remove all dust, oil and solvent from the surface with a lint-free cloth lightly dampened with water and denatured alcohol mixed 50:50. Apply pre-stain sealer and /or wood stain as desired, prior to grain filling, as required by finishing schedule. HSF5000 Neutral Base can be tinted with water-soluble dyes and/or pigments to create a ground color for natural grain color enhancement. Spray, brush or roll-apply HSF5000 onto prepared substrate. Apply HSF5000 at a 2-3mil wet film thickness per coat. Allow each coat air dry for a minimum of 1 hour at room temperature. Sand each coat as described above with 320-grit sandpaper to remove surface defects. Apply a minimum of 2 coats to obtain a filled grain effect. (Note: Different wood species require more/fewer coats of filler. Make a test panel to determine the exact number of coats of HSF5000 needed.) Repeat if necessary to complete fill in negative grain. Allow 2 hours drying time between each filler application to ensure proper drying of underlying filler. Re-apply stain or dye if required to even off color tone. Pigmented Base Version (HSF52xx & HSF53xx): All surfaces to be finished must be clean, dry and free of excess contamination. Remove all dust, oil and solvent from the surface with a lint-free cloth lightly dampened with water and denatured alcohol mixed 50:50. For MDF priming, sand surface with 180-grit aluminum oxide sandpaper to improve adhesion of primer. Apply the first of primer reduced with water 10-20%, at 2-3 mils wet. Allow the first coat to dry for a minimum of 60 minutes. Sand first coat of reduced HSF5000 with 320-grit sandpaper to remove surface defects. Apply second coat of pigmented HSF5000 to obtain complete hiding of substrate.